Conventionally, an accumulator fuel injection mechanism capable of performing multi-stage injection has been employed to simultaneously achieve reduction in PM (particulate matter), NOx (nitrogen oxide), and noise, for example. As publicly known, in an engine including such an accumulator fuel injection device capable of performing multi-stage injection, a pre-injection performed ahead of a main injection achieves stable combustion in a low-load state in which a load on the engine is relatively low (refer to Patent Document 1).